<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <meta name="viewport" content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
</head>
<body>
    
    <input type="text" placeholder="圆的半径" id="a">
    <input type="text" placeholder="圆的周长" id="b">
    <input type="text" placeholder="圆的面积" id="c">
    
    
    
    
    <script src="./js/script.js"></script>
    
</body>
</html>